Less waste corn, more land in soybeans, and the switch to genetically modified crops: Trends with important implications for wildlife management
Gary L. Krapu, D.A. Brandt, R. R. Cox Jr.
2004, Wildlife Society Bulletin (32) 127-136
American agriculture has provided abundant high-energy foods for migratory and resident wildlife populations since the onset of modern wildlife management. Responding to anecdotal evidence that corn residues are declining in cropland, we remeasured waste corn post-harvest in the Central Platte River Valley (CPRV) of Nebraska during 1997 and 1998 to...
Feasibility of measuring dissolved carbon dioxide based on head space partial pressures
B.J. Watten, C.E. Boyd, M.F. Schwartz, S.T. Summerfelt, B. L. Brazil
2004, Aquacultural Engineering (30) 83-101
We describe an instrument prototype that measures dissolved carbon dioxide (DC) without need for standard wetted probe membranes or titration. DC is calculated using Henry's Law, water temperature, and the steady-state partial pressure of carbon dioxide that develops within the instrument's vertical gas-liquid contacting chamber. Gas-phase partial pressures were determined...
The rotating movement of three immiscible fluids - A benchmark problem
M. Bakker, Essink G.H.P. Oude, C.D. Langevin
2004, Journal of Hydrology (287) 270-278
A benchmark problem involving the rotating movement of three immiscible fluids is proposed for verifying the density-dependent flow component of groundwater flow codes. The problem consists of a two-dimensional strip in the vertical plane filled with three fluids of different densities separated by interfaces. Initially, the interfaces between the fluids...
Microforms in gravel bed rivers: Formation, disintegration, and effects on bedload transport
K. Strom, A.N. Papanicolaou, N. Evangelopoulos, M. Odeh
2004, Journal of Hydraulic Engineering (130) 554-567
This research aims to advance current knowledge on cluster formation and evolution by tackling some of the aspects associated with cluster microtopography and the effects of clusters on bedload transport. The specific objectives of the study are (1) to identify the bed shear stress range in which clusters form and...
Earthquake source parameters determined by the SAFOD Pilot Hole seismic array
K. Imanishi, W.L. Ellsworth, S. G. Prejean
2004, Geophysical Research Letters (31)
We estimate the source parameters of #3 microearthquakes by jointly analyzing seismograms recorded by the 32-level, 3-component seismic array installed in the SAFOD Pilot Hole. We applied an inversion procedure to estimate spectral parameters for the omega-square model (spectral level and corner frequency) and Q to displacement amplitude spectra. Because...
Trace metal records of regional paleoenvironmental variability in Pennsylvanian (Upper Carboniferous) black shales
A.M. Cruse, T.W. Lyons
2004, Chemical Geology (206) 319-345
Regional geochemical differences within a laterally continuous, cyclic Pennsylvanian (Upper Carboniferous) shale in midcontinent North America are interpreted in light of models of glacioeustatic forcing and new views on water-column paleoredox stability and trace-metal behavior in black shale environments. Specifically, we characterize differences in transition metal (Fe, Mn, Mo, V,...
USGS tethered ACP platforms: New design means more safety and accuracy
S. E. Morlock, J. A. Stewart, M.S. Rehmel
2004, Hydro International (8) 45-47
The US Geological Survey has developed an innovative tethered platform that supports an Acoustic Current Profiler (ACP) in making stream-flow measurements (use of the term ACP in this article refers to a class of instruments and not a specific brand name or model). The tethered platform reduces the hazards involved...
Lava lakes on Io: Observations of Io's volcanic activity from Galileo NIMS during the 2001 fly-bys
R. M. C. Lopes, L.W. Kamp, W. D. Smythe, P. Mouginis-Mark, J. Kargel, J. Radebaugh, E. P. Turtle, J. Perry, D.A. Williams, R. W. Carlson, S. Doute
2004, Icarus (169) 140-174
Galileo's Near-Infrared Mapping Spectrometer (NIMS) obtained its final observations of Io during the spacecraft's fly-bys in August (I31) and October 2001 (I32). We present a summary of the observations and results from these last two fly-bys, focusing on the distribution of thermal emission from Io's many volcanic regions that give...
Uptake pathway for Ag bioaccumulation in three benthic invertebrates exposed to contaminated sediments
H. Yoo, J.-S. Lee, B.-G. Lee, I.T. Lee, C.E. Schlekat, C.-H. Koh, S. N. Luoma
2004, Marine Ecology Progress Series (270) 141-152
We exposed 3 benthic invertebrates, the clam Macoma balthica, the polychaete Neanthes arenaceodentataand the amphipod Leptocheirus plumulosus, to Ag-contaminated sediments to evaluate the relative importance of various uptake routes (sediments, porewater or overlying water, and supplementary food) for Ag bioaccumulation. Silver bioaccumulation was evaluated at 4 levels of sediment Ag (0.1, 0,3, 1,2...
Landslides triggered by the 2002 Denali fault, Alaska, earthquake and the inferred nature of the strong shaking
R.W. Jibson, E. L. Harp, W. Schulz, D. K. Keefer
2004, Earthquake Spectra (20) 669-691
The 2002 M7.9 Denali fault, Alaska, earthquake triggered thousands of landslides, primarily rock falls and rock slides, that ranged in volume from rock falls of a few cubic meters to rock avalanches having volumes as great as 15 ?? 106 m3. The pattern of landsliding was unusual; the number of...
Origin of the Blue Ridge escarpment along the passive margin of Eastern North America
J.A. Spotila, G.C. Bank, P.W. Reiners, C. W. Naeser, N. D. Naeser, B.S. Henika
2004, Basin Research (16) 41-63
The Blue Ridge escarpment is a rugged landform situated within the ancient Appalachian orogen. While similar in some respects to the great escarpments along other passive margins, which have evolved by erosion following rifting, its youthful topographic expression has inspired proposals of Cenozoic tectonic rejuvenation in eastern North America. To...
Moment-tensor solutions estimated using optimal filter theory: Global seismicity, 2002
S.A. Sipkin, M.D. Zirbes
2004, Physics of the Earth and Planetary Interiors (145) 203-217
Moment-tensor solutions, estimated using optimal filter theory, are listed for 306 moderate-to-large size earthquakes that occurred during 2002. ?? 2004 Published by Elsevier B.V....
Three-dimensional distribution of gas hydrate beneath southern Hydrate Ridge: Constraints from ODP Leg 204
A.M. Trehu, P.E. Long, M.E. Torres, G. Bohrmann, F.R. Rack, T. S. Collett, D.S. Goldberg, A.V. Milkov, M. Riedel, P. Schultheiss, N.L. Bangs, S. R. Barr, W.S. Borowski, George E. Claypool, M.E. Delwiche, G.R. Dickens, E. Gracia, G. Guerin, M. Holland, J.E. Johnson, Y.-J. Lee, C.-S. Liu, X. Su, B. Teichert, H. Tomaru, M. Vanneste, M. E. Watanabe, J.L. Weinberger
2004, Earth and Planetary Science Letters (222) 845-862
Large uncertainties about the energy resource potential and role in global climate change of gas hydrates result from uncertainty about how much hydrate is contained in marine sediments. During Leg 204 of the Ocean Drilling Program (ODP) to the accretionary complex of the Cascadia subduction zone, we sampled the gas...
Using chromium stable isotope ratios to quantify Cr(VI) reduction: Lack of sorption effects
A.S. Ellis, T.M. Johnson, T.D. Bullen
2004, Environmental Science & Technology (38) 3604-3607
Chromium stable isotope values can be effectively used to monitor reduction of Cr(VI) in natural waters. We investigate effects of sorption during transport of Cr(VI) which may also shift Cr isotopes values, complicating efforts to quantify reduction. This study shows that Cr stable isotope fractionation caused by...
The nucleus of Comet Borrelly: A study of morphology and surface brightness
J. Oberst, Elpitha Howington-Kraus, Randolph L. Kirk, Laurence A. Soderblom, B. Buratti, M. Hicks, R. Nelson, D. Britt
2004, Icarus (167) 70-79
Stereo images obtained during the DS1 flyby were analyzed to derive a topographic model for the nucleus of Comet 19P/Borrelly for morphologic and photometric studies. The elongated nucleus has an overall concave shape, resembling a peanut, with the lower end tilted towards the camera. The bimodal character of surface-slopes and...
Estimating tectonic history through basin simulation-enhanced seismic inversion: Geoinformatics for sedimentary basins
K. Tandon, K. Tuncay, K. Hubbard, J. Comer, P. Ortoleva
2004, Geophysical Journal International (156) 129-139
A data assimilation approach is demonstrated whereby seismic inversion is both automated and enhanced using a comprehensive numerical sedimentary basin simulator to study the physics and chemistry of sedimentary basin processes in response to geothermal gradient in much greater detail than previously attempted. The approach not only reduces costs by...
Estimating survival and recruitment in a freshwater mussel population using mark-recapture techniques
R.F. Villella, D. R. Smith, D. P. Lemarie
2004, American Midland Naturalist (151) 114-133
We used a mark-recapture method and model averaging to estimate apparent survival, recruitment and rate of population growth in a native freshwater mussel population at a site on the Cacapon River, which is a tributary to the Potomac River. Over 2200 Elliptio complanata, E. fisheriana and Lampsilis cariosa were uniquely...
Conservative and reactive solute transport in constructed wetlands
Steffanie H. Keefe, Larry B. Barber, Robert L. Runkel, Joseph N. Ryan, Diane M. McKnight, Roland D. Wass
2004, Water Resources Research (40)
The transport of bromide, a conservative tracer, and rhodamine WT (RWT), a photodegrading tracer, was evaluated in three wastewater‐dependent wetlands near Phoenix, Arizona, using a solute transport model with transient storage. Coupled sodium bromide and RWT tracer tests were performed to establish conservative transport and reactive parameters in constructed wetlands...
Log Pearson type 3 quantile estimators with regional skew information and low outlier adjustments
V.W. Griffis, Jery R. Stedinger, T.A. Cohn
2004, Water Resources Research (40)
The recently developed expected moments algorithm (EMA) [Cohn et al., 1997] does as well as maximum likelihood estimations at estimating log‐Pearson type 3 (LP3) flood quantiles using systematic and historical flood information. Needed extensions include use of a regional skewness estimator and its precision to be consistent with Bulletin 17B. Another...
Modeling sorption of divalent metal cations on hydrous manganese oxide using the diffuse double layer model
J.W. Tonkin, L.S. Balistrieri, J.W. Murray
2004, Applied Geochemistry (19) 29-53
Manganese oxides are important scavengers of trace metals and other contaminants in the environment. The inclusion of Mn oxides in predictive models, however, has been difficult due to the lack of a comprehensive set of sorption reactions consistent with a given surface complexation...
Joint inversion of gravity and arrival time data from Parkfield: New constraints on structure and hypocenter locations near the SAFOD drill site
S. Roecker, C. Thurber, D. McPhee
2004, Geophysical Research Letters (31)
Taking advantage of large datasets of both gravity and elastic wave arrival time observations available for the Parkfield, California region, we generated an image consistent with both types of data. Among a variety of strategies, the best result was obtained from a simultaneous inversion with a stability requirement that encouraged...
Effects of natal departure and water level on survival of juvenile snail kites (Rostrhamus sociabilis) in Florida
V.J. Dreitz, W.M. Kitchens, D.L. DeAngelis
2004, The Auk (121) 894-903
Survival rate from fledging to breeding, or juvenile survival, is an important source of variation in lifetime reproductive success in birds. Therefore, determining the relationship between juvenile survival and environmental factors is essential to understanding fitness consequences of reproduction in many populations. With increases in density of individuals and depletion...
Radon (222Rn) in ground water of fractured rocks: A diffusion/ion exchange model
W.W. Wood, T. F. Kraemer, A. Shapiro
2004, Ground Water (42) 552-567
Ground waters from fractured igneous and high‐grade sialic metamorphic rocks frequently have elevated activity of dissolved radon (222Rn). A chemically based model is proposed whereby radium (226Ra) from the decay of uranium (238U) diffuses through the primary porosity of the rock to the water‐transmitting fracture where...
A modern vs. Permian black shale - the hydrography, primary productivity, and water-column chemistry of deposition
D.Z. Piper, R.B. Perkins
2004, Chemical Geology (206) 177-197
The sediment currently accumulating in the Cariaco Basin, on the continental shelf of Venezuela, has an elevated organic-carbon content of approximately 5%; is accumulating under O2-depleted bottom-water conditions (SO42- reduction); is composed dominantly of foraminiferal calcite, diatomaceous silica, clay, and silt; and is dark greenish gray in color. Upon lithification,...
Mineralogical and geochemical controls on the release of trace elements from slag produced by base- and precious-metal smelting at abandoned mine sites
N.M. Piatak, R.R. Seal II, J. M. Hammarstrom
2004, Conference Paper, Applied Geochemistry
Slag collected from smelter sites associated with historic base-metal mines contains elevated concentrations of trace elements such as Cu, Zn and Pb. Weathering of slag piles, many of which were deposited along stream banks, potentially may release these trace elements into the environment. Slags were sampled from the Ely and...
